Abstract: Methods, systems, and computer-readable media for request authorization using service coordination are disclosed. An authorization data structure and an operation data structure are selected based at least in part on a request for an operation. The authorization data structure comprises a directed acyclic graph representing a flow of data between service operations associated with authorization of the operation, and the operation data structure comprises a directed acyclic graph representing a flow of data between a service operations associated with execution of the operation. Authorization of the operation is attempted using the authorization data structure, comprising invoking one or more of the service operations associated with authorization. If the authorization is successful, then the execution of the operation is initiated using the operation data structure, comprising invoking one or more of the service operations associated with execution.

Abstract: Methods, systems, and computer-readable media for a customer-facing service for service coordination are disclosed. Via a request gateway, a request to perform an operation is received. A data structure associated with the operation is retrieved. The data structure is generated based at least in part on one or more models and an indication of service operations. The one or more models are formatted using a modeling language associated with the request gateway. The data structure comprises a directed acyclic graph representing a flow of data between the service operations, and the flow of data is determined based at least in part on analysis of typed fields of the service operations. The request is processed to perform the operation based at least in part on the data structure, including invoking a plurality of the service operations using traversal of the directed acyclic graph.

Abstract: Methods, systems, and computer-readable media for request authorization using service coordination are disclosed. An authorization data structure and an operation data structure are selected based at least in part on a request for an operation. The authorization data structure comprises a directed acyclic graph representing a flow of data between service operations associated with authorization of the operation, and the operation data structure comprises a directed acyclic graph representing a flow of data between a service operations associated with execution of the operation. Authorization of the operation is attempted using the authorization data structure, comprising invoking one or more of the service operations associated with authorization. If the authorization is successful, then the execution of the operation is initiated using the operation data structure, comprising invoking one or more of the service operations associated with execution.

Abstract: A service workflow agent associated with a particular service of a provider network identifies a repository in which workflow descriptors indicative of tasks to be performed by the service are stored. In response to determining that a modification has been applied at one such repository, the agent examines a particular workflow descriptor stored in the repository. The agent initiates an attempt to implement a first task indicated in the descriptor. Subsequently, the agent updates the descriptor in accordance with an optimistic concurrency control technique to indicate a status of the first task.

Abstract: Methods, systems, and computer-readable media for request authorization using service coordination are disclosed. An authorization data structure and an operation data structure are selected based at least in part on a request for an operation. The authorization data structure comprises a directed acyclic graph representing a flow of data between service operations associated with authorization of the operation, and the operation data structure comprises a directed acyclic graph representing a flow of data between a service operations associated with execution of the operation. Authorization of the operation is attempted using the authorization data structure, comprising invoking one or more of the service operations associated with authorization. If the authorization is successful, then the execution of the operation is initiated using the operation data structure, comprising invoking one or more of the service operations associated with execution.

Abstract: Technologies are described herein for adaptive polling based upon demand. A data source is polled for data at a first polling frequency. A request is received for a page or other type of resource that includes the data, and the data is provided in response to the request. Subsequently, the data source is polled for the data at a second polling frequency greater than the first polling frequency. Status messages are also received indicating a status of a display of the page. The polling frequency may be adjusted based on the status messages. For example, the polling frequency may be increased if a status message indicates that a user is viewing the data. The polling frequency may be decreased if a status message indicates that the data is not being viewed or that a page or other type of resource for presenting the data has been closed.

Abstract: Systems with multiple components managing storage may implement efficient storage reclamation. A storage reclamation event may be detected for a system component. An indication to a request dispatching mechanism may be made which indicates that the system component is unable to perform further tasks in order to perform storage reclamation. A storage reclamation operation, such as a stop-the-world garbage collection technique, or a service process restart may be performed to reclaim at least some storage. Upon completion of the storage reclamation operation, an indication may be made to the request distribution mechanism that the service process has resumed performing tasks for the system. In some embodiments, a gossip protocol communicating availability information to different nodes of a distributed system may provide information to schedule storage reclamation operations at different compute nodes of the distributed system.